/*
 *   This program is free software: you can redistribute it and/or modify
 *   it under the terms of the GNU General Public License as published by
 *   the Free Software Foundation, either version 3 of the License, or
 *   (at your option) any later version.
 *
 *   This program is distributed in the hope that it will be useful,
 *   but WITHOUT ANY WARRANTY; without even the implied warranty of
 *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *   GNU General Public License for more details.
 *
 *   You should have received a copy of the GNU General Public License
 *   along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

/*
 *    OutputZipper.java
 *    Copyright (C) 2000-2012 University of Waikato, Hamilton, New Zealand
 *
 */

package weka.experiment;

import java.io.DataOutputStream;
import java.io.File;
import java.io.FileOutputStream;
import java.util.zip.GZIPOutputStream;
import java.util.zip.ZipEntry;
import java.util.zip.ZipOutputStream;

/**
 * OutputZipper writes output to either gzipped files or to a multi entry zip
 * file. If the destination file is a directory each output string will be
 * written to an individually named gzip file. If the destination file is a
 * file, then each output string is appended as a named entry to the zip file
 * until finished() is called to close the file.
 *
 * @author Mark Hall (mhall@cs.waikato.ac.nz)
 * @version $Revision$
 */
public class OutputZipper {

    File m_destination;
    DataOutputStream m_zipOut = null;
    ZipOutputStream m_zs = null;

    /**
     * Constructor.
     * 
     * @param destination a destination file or directory
     * @throws Exception if something goes wrong.
     */
    public OutputZipper(File destination) throws Exception {

        m_destination = destination;

        // if a directory is specified then use gzip format, otherwise
        // use zip
        if (!m_destination.isDirectory()) {
            m_zs = new ZipOutputStream(new FileOutputStream(m_destination));
            m_zipOut = new DataOutputStream(m_zs);
        }
    }

    /**
     * Saves a string to either an individual gzipped file or as an entry in a zip
     * file.
     * 
     * @param outString the output string to save
     * @param name      the name of the file/entry to save it to
     * @throws Exception if something goes wrong
     */
    public void zipit(String outString, String name) throws Exception {
        File saveFile;
        ZipEntry ze;

        if (m_zipOut == null) {
            saveFile = new File(m_destination, name + ".gz");
            DataOutputStream dout = new DataOutputStream(new GZIPOutputStream(new FileOutputStream(saveFile)));

            dout.writeBytes(outString);
            dout.close();
        } else {
            ze = new ZipEntry(name);
            m_zs.putNextEntry(ze);
            m_zipOut.writeBytes(outString);
            m_zs.closeEntry();
        }
    }

    /**
     * Closes the zip file.
     * 
     * @throws Exception if something goes wrong
     */
    public void finished() throws Exception {
        if (m_zipOut != null) {
            m_zipOut.close();
        }
    }

    /**
     * Main method for testing this class
     */
    public static void main(String[] args) {

        try {
            File testF = new File(new File(System.getProperty("user.dir")), "testOut.zip");
            OutputZipper oz = new OutputZipper(testF);

            /*
             * OutputZipper oz = new OutputZipper( new
             * File(System.getProperty("user.dir")));
             */
            oz.zipit("Here is some test text to be zipped", "testzip");
            oz.zipit("Here is a second entry to be zipped", "testzip2");
            oz.finished();
        } catch (Exception ex) {
            ex.printStackTrace();
            System.err.println(ex.getMessage());
        }
    }
}
